Obesity is a major public health problem with associated health care costs estimated to be in excess of $98 billion to 129 billion per year. However, it is clear that fatter children have an increased risk of obesity in adulthood and the severity of obesity in adulthood when it begins in childhood is considerably greater. Furthermore, even before reaching adulthood, overweight and obese children are experiencing medical and psychosocial effects related to their overweight condition. The medical community now recognizes that childhood obesity represents a chronic disease. Treating it is frustrating and time consuming for most physicians. Many cite lack of expertise or resources as reasons for shying away from addressing their patients overweight or obesity problem. Current recommendations for the identification, evaluation, and treatment of childhood obesity are based on expert consensus since generalizable evidence-based approaches to evaluation and treatment are limited. These guidelines emphasize both parent and child behavioral changes that will result in healthy eating and an active lifestyle. Regular contact of parent and child with the clinician is emphasized, yet little is known about the intensity of intervention and follow-up that is required to treat and sustain both weight loss and the positive health benefits that accompany weight loss achieved through healthy lifestyle changes promoted in the primary care setting. In order to answer this question, we plan a 6-month intense family-centered intervention, followed by a 6-month maintenance phase, primarily directed at parents of overweight and obese children, ages 4 to 7 years, delivered at the primary care provider's office which will be compared to an enhanced standard of care that will be delivered at the primary care provider's office. Primary care sites will be randomized to receive either the intervention or the enhanced standard of care. Participants will be followed for a total of 2 years.